My Aquifer > Septic System Basics > How do you construct a tile bed?
Tiles beds are typically constructed using 4-inch diameter pipe, with 2 inches of gravel layered above the pipe and at least 6 inches of gravel below.
The pipes are buried 2 to 3 feet below grade level (depending on the area), below the maximum frost depth whenever possible.
The size of the tile bed (length and number of branches) is dependent upon the permeability of the soil, and the maximum load anticipated. The size of the house, the number of residents, and the number of toilets and faucets all translate to an expected volume of wastewater being produced. The maximum amount of such effluent that could be generated is the maximum load that the system will receive - typically a saftey margin is added to the design.
TAKE A LOOK at a tile bed layout diagram.